Infineon Technologies, Philips and several other chipmakers could face fines after European competition regulators said they may have colluded to fix prices for chips used in mobile SIM cards, passports and bank cards.

The European Commission said it sent documents setting out its concerns to companies it suspected of behaving like a cartel in the market for smart card chips, which are also used in pay television systems and identity cards.

It did not identify the companies, but Germany's Infineon (Neubiberg, Germany) and Dutch company Philips (Amsterdam, Netherlands) confirmed they had received the statement of objections.

Philips said the 90-page EU document it was sent referred to allegations of wrongdoing in the years 2003 and 2004. Since then it has sold its semiconductor business.

The companies would face fines of up to 10 percent of their global revenue if the accusations are proven.

The Commission said it had issued the charge sheet after talks with the companies to settle the case broke down. During the talks, it said, the companies were offered a 10 percent reduction in fines if they admitted taking part in a cartel.

The case began in January 2009 with raids on companies in several EU countries. The firms can ask for a closed-door hearing to defend themselves before EU antitrust officials and national competition regulators.

NXP Semiconductors (Eindhoven, Netherlands) and STMicroelectronics (Geneva, Switzerland), both of which had previously said they were under investigation, said on Monday they had not received the EU document.

Gemalto (Amsterdam, Netherlands), the world's largest maker of smart cards, said it was not a target of the investigation.